The error was discovered “when McLaren Bay Region began to consolidate its pension programs into the corporation’s pension programs,” said Kurt Miller, director of marketing and public relations for McLaren Bay Region.

The hospital has been with the McLaren system since 2002.

“The letters to those affected went out by last week,” Miller said.

Seventy employees were underpaid a total of $1.1 million, and 213 employees were overpaid a total of $832,000, according to a McLaren Bay Region news release issued Tuesday, Jan. 15.

Those who were underpaid were people who retired late, after the age of 65, and those who were over-paid were people who retired early, or before the age of 65.

Those who were overpaid must choose between writing a check for the total amount they owe or having their monthly pension benefit reduced to correct the error and make up for the over-payments.

“They make a decision by Feb. 1, and the calculations and payments and repayments in either direction begin March 1.”

Miller said no particular department was affected.

“It’s a regrettable error, and these things happen from time to time,” he said. “...We’re doing our best to be able to work with people to be able to correct the situation.”

Sharon Roberts, who retired from the pharmacy department at the former Bay Medical Center almost 13 years ago, told MLive she is being asked to repay $8,689.52. Roberts said she was receiving $311.65 monthly, which her letter said was an overpayment of $38.70 per month.

After doing her own calculations, she came up with a total overpayment of $6,037.20.

“We don’t know where this extra is coming from, if it's interest or inflation,” she said. “What I want to know is, how come it is that they waited 13 years before anybody finds this thing?”

Miller declined to comment on individual cases and encouraged anyone who is affected by the error and has questions to call human resources at 866-238-2419.